Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Total Retirement Expense	$ 6	$ 9	$ 26	$ 34
Settlement charges	22	62	73	81
Nonqualified Plan [Member]
Defined contribution plans expense	0	0	0	1
Qualified Plan [Member]
Defined contribution plans expense	20	22	65	71
Pension Plan [Member]
Service cost	1	1	4	3
Interest cost	25	27	79	83
Expected return on assets	(55)	(56)	(168)	(170)
Recognition of net actuarial (gain) loss	8	7	24	22
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(21)	(21)	(61)	(62)
Supplemental Employee Retirement Plan [Member]
Service cost	0	0	0	0
Interest cost	5	5	16	17
Recognition of net actuarial (gain) loss	2	3	6	7
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	7	8	22	24
Other Postretirement Benefits Plan [Member]
Service cost	0	0	0	0
Interest cost	1	1	4	4
Recognition of net actuarial (gain) loss	(2)	(1)	(4)	(3)
Amortization of prior service credit	0	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ (1)	$ 0	$ 0	$ 1